Conventionally, optical fiber is used for high-speed data transmission at low costs. Optical transceiver is used to convert electrical signal to optical signal and vise versa. Traditionally, coupling of optical signal from optical transceiver to optical fiber requires dedicated high-precision optical connectors. Recently, there is a need to introduce optical data bus to consumer electronic appliances to cope with the ever-increasing bandwidth demands for, e.g., transferring multi-media content from storage to the appliances. The enable this kind of applications, USB connector interfaces, which are commonly found in computers and numerous consumer appliances, were adopted to facilitate optical transmission.
In the traditional implementation of this type of optical interface, optical transceivers are located in transceiver housings outside of the USB connectors and on a printed-circuit board within the appliance enclosure. High-speed electronic signal is fed into the transceiver through the housing and is converted to optical signal. The optical signal is first coupled into a short piece of fiber jumper which is attached to the transceiver optical port during assembly process. The other end of the jumper is terminated with a plug assembly adopted for assembling into the back of USB connector. External fiber cable is terminated with a receptacle assembly which takes the shape of USB plug and can be inserted into the USB connector and aligned with the jumper plug assembly within the USB connector housing. When the plug and receptacle are engaged, optical signal is coupled from the jumper cable into the external cable and vise versa. Thus a duplex optical link is formed.
With the structure of the above-mentioned optical link configuration, the optical transceiver and corresponding housing occupies real estate on the PCB within the appliance. In addition, the use of additional jumper cable to connect optical transceiver and external cable causes optical loss and may affect signal transmission quality. As a result, there is a need to provide an improved USB connector design which can simultaneously serve as an active optical transceiver to overcome the disadvantages mentioned above.